The present invention relates to a novel metallurgical coating system which affords a degree of protection hitherto unavailable to metallic components which are subjected to unusually severe operating conditions. In particular, the coating system is especially useful in severe chemical environments in which corrosion resistance and non-stick properties are desirable.
Materials which provide effective resistance to ordinary problems of corrosion are well-known in the art. Such materials include, for example, the various stainless steels and other steel alloys.
It also is known that other materials providing greater resistance to corrosion are available for use in environments where corrosion is a more severe problem. One class of materials which has been shown to be useful in such environments is the class of nickel-base alloys. In addition to nickel, such alloys typically contain varying amounts of molybdenum, chromium, iron, and other metals. Particularly effective are nickel-base alloys which contain relatively large percentages of molybdenum. While the materials described above perform well for their intended applications, it has been found that these materials suffer undesirably rapid and extensive corrosion and failure under extremely severe operating conditions. We have now found that the problem of corrosion in severe chemical environments can be mitigated by the use of the unique coating system described herein.